I've also built complex systems that have been run in production for years with relatively few typo-related problems. The way I do it is with the design patterns like the one I just mentioned, which is also what TeMPOraL was talking about (and I guess you missed it.)
If you have the same kind of confirmation whenever you delete a thing, whether it's an important thing or not, you're designing a system which encourages bad auto-pilot habits.
You'll also note that Amazon's description of the way that they plan on changing their system is intended to fire extra confirmation only when it looks like the operator is about to make a massive mistake. That follows the design pattern I'm suggesting.